With the increasing use of screen-based devices, in particular handheld devices such as mobile phones, smartphones, and tablet computers or tablets, the issue of screen readability has become more prominent, for at least the following reasons. Firstly, the size of screens which are provided as displays with this class of devices is limited so as to enable users to accommodate their devices in a pocket of their shirt, jacket, or trousers, or to be carried in a briefcase. As a consequence, the size of displayed content is limited. In particular, this limits the range of font sizes which are reasonable for displaying text the screen of such a device. Second, readability is negatively affected by inadvertent displacements of the device, such as vibrations or sudden movements, relative to the user's eye or eyes gazing at the screen. The issue of inadvertent displacements or vibrations has emerged due to the increasing use of handheld devices while walking, driving in a car, riding the bus or train, and the like.
The human eye is able to track the movements or acceleration patterns of a moving object, such as a screen displaying content, up to a certain frequency and amplitude, thus managing to maintain proper focus on desired parts of the screen. Hence, a person gazing at a screen for viewing content is able to maintain readability up to a certain frequency and amplitude of change in gaze.
In the present context, the term ‘readability’ relates to the ease with which a viewer can understand a text displayed on the screen. It encompasses ‘legibility’, which is a measure of how easily a reader can distinguish individual letters or characters from each other. More general, displayed content may include not only text but also other graphical objects such as images, pictures, buttons, icons, and the like.
Known solutions which address the issue of readability of devices comprising screens for displaying content are based on utilizing user settings for adjusting a font size which is used for displaying text or a zoom factor which is applied to enlarge parts of the content, or the entire content, displayed on the screen.
U.S. 2013/0009962 A1 discloses solutions for automatically adjusting displayed information by selecting font sizes or a zoom level based on settings relating to the user, such as the user's vision or age, as well as ambient light, screen settings, and the displayed information, e.g., foreground and background colors of the displayed information.
While known solutions take certain contextual or environmental circumstances such as ambient light into account, it is not assessed whether the user viewing content displayed on a screen of the device in fact suffers from inferior readability before adjusting the displayed content or information.